A new broadband matched field processor

It is well known that the use of multiple frequencies helps to reduce uncertainty and to improve resolution for matched field processing. This can be extremely important for the estimation of geoacoustic (bottom) parameters and usually means averaging ambiguity surfaces either incoherently or coherently (if the source spectrum is known) for the linear or minimum variance processors. However, a new approach requires that only the minimum processor values be retained over all the frequencies considered. This presentation will show how this method improves resolution and sidelobe reduction (for the simple incoherent method) both for the linear and for the minimum variance processing. Of course, one never gets something for nothing. This improvement comes at the cost of using only those frequencies which show high-matched field values, usually the low frequencies (25–75 Hz), for geoacoustic inversion. If some frequency component is strongly degraded, then the method will not work. The behavior of this new pro...